Mesoscale imaging of neuronal activity coupled with light-evoked motor mapping reveal movement-specific spatiotemporal patterns of cortical activation in awake mice

We developed an all-optical system that couples large-scale cortical imaging with chronic light-based motor mapping in awake mice. By AAV-mediated cortical transfection, we induced the co-expression of the red-shifted genetically encoded calcium indicator and a light-sensitive optogenetic actuator ChR2 over both the rostral and caudal forelimb areas, which was stable over several months. No evidence of cross-talk was detected during illumination of ChR2+ neurons with the light source used for RCaMP1a excitation. Light-based motor mapping coupled with wide-field imaging of neuronal activation in awake mice revealed spatiotemporal patterns of cortical activation specific for movement category.